Chip resistors are generally manufactured by forming resistive films and electrode layers on an insulated substrate by printing or the like process, and cutting crisscross or punching the substrate. In this case, the final adjustment of resistance is often made by providing a slit or a slot in the resistive film.
Patent Publications 1 and 2 propose rectangular plate type chip resistors wherein the insulating substrate is not used, and instead a resistive alloy plate of a certain thickness is provided with electrode layers.
In the method of manufacturing chip resistors disclosed in Patent Publication 1, an insulating layer is formed at a plurality of positions on the upper and lower faces of a resistive metal plate, a surface electrode layer and a back electrode layer are formed along both sides of each insulating layer, and the resistive alloy plate is cut in parallel to the insulating layer, which cutting requires an expensive metal mold. Then an end electrode is required to be formed by soldering along both sides of the cut alloy plate, and after this, the alloy plate is further required to be cut in the transverse direction of the insulating layer for obtaining rectangular plate type chip resistors. As such, in the manufacturing method disclosed in Publication 1 wherein the end electrodes are formed after the first cutting step and then another cutting step is performed, the production process tends to be complex. In addition, since the end electrode cannot be formed together with the surface and back electrodes, the chip resistors manufactured by such a method have different thickness and materials of electrodes, so that the adhesion of the electrodes and the reliability of the electrode structure are not always sufficient.
Patent Publication 2 discloses that, in order to adjust the resistance of the disclosed rectangular plate type chip resistor to a predetermined value, a plurality of slots or slits need to be formed in the resistor element. This publication is silent about a convenient method of manufacturing chip resistors which enables adjustment of resistance without forming such slits and the like.
Patent Publication 1: JP-2004-319787-A
Patent Publication 2: JP-7-38321-B